Method of filling aerosol containers and aerosol valve structure adapted for such method



June 4, 1968 E, H, GREEN ET AL 3,386,479

METHOD 0F FILLING AEROSOL CONTAINERS AND AEROSOL VALVE STRUCTURE ADAPTED FOR SUCH METHOD Filed April 9, 1965 PRIOR ART aand "Zim June 4, 1968 E. H. GREEN ET AI- 3,336,479

METHOD OF FILLING AEROSOL CONTAINERS AND AEROSOL VALVE v STRUCTURE ADAPTED FOR SUCH METHOD Filed April 9, 1965 2 SheetsfShee. 2

35 um f@ l v l l i United States Patent O 3 386 479 METHOD or mLLrNG nnosor. coN'rArNnns AND AEROSOL VALVE STRUCTURE ADAETED FOR SUCH METHOD Edward H. Green, 11 Army Trai Road, Addison, Eli. 60101, and David S. Tillotson, 1260 Greenwood Ave., Deerfield, Ill. 60015 Filed Apr. 9, 1965, Ser. No. 446,900 7 Claims. (Cl. 141-3) ABSTRACT OF THE DISCLOSURE A valve assembly for use with aerosol canister, and a method of filling an aerosol canister adapted to said valve assembly. The valve lassembly utilizing a valve housng connected to an aerosol canister; an apertured gasket associated with the housing; a valve plunger reciprocal within the housing under the influence of a spring such that the upper peripheral surface of the plunger sealingly engages the gasket; guide means on the valve plunger for cooperating with the tapered tip of a nozzle inserted in said housing for the introduction of pressurized product therein to axially displace the valve plunger and permit filling of the canister, the aforementioned cooperation of the guide means with the nozzle tip being effective to center the valve plunger with respect to the apertured gasket upon cessation of the introduction of pressurized product and the allowance of the valve plunger to return to sealing engagement with the gasket.

This invention relates generally to the art of pressurized packages, and more particularly, is concerned with an improvement in the constructlon of valve assemblies for such pressurized packages and with a novel method of filling pressurized packages provided with a valve assembly of this character.

One type of pressurized package commonly encountered may be referred to as a spray can. Such pressurized package comprises a canister of a material adapted to withstand the pressure of the product it contains. The canister has a relatively wide opening at one end thereof, referred to hereinafter and without limitation, as the upper end, since it is located `at the top of a conventional can in its normal, upright position. Other terms used herein to refer to the relative position of the can, such as, downward, lower end, top, bottom, are intended to refer to the can in the same upright position.

The above-mentioned opening usually is of circular configuration, bordered by a rolled rim and is adapted to receive a cover member equipped with a suitable selfsealing valve assembly which includes a plunger movable between sealed and unsealed position. After the cover member has been tightly sealed to the rolled rim, the canister may be filled through the valve assembly and discharged therethrough as well, the valve assembly being located generally within the interior of the canister and depending from the inner side of the cover member.

Certain difiiculties have been encountered in filling canisters through a valve of the aforementioned type. Prior valve structures and filling methods were such that subsequent to completion of the filling process, the plunger would return to its sealed position and yet could be out of alignment with the passageway through which the filling is accomplished. When a spray head having a depending stem subsequently is inserted with its stem through the same passageway, an undesired leakage of product may occur while the stem is brought into final engagement with the valve plunger. Such leakage principally is due to misalignment of the plunger.

The object of this invention is to overcome the above described disadvantages by providing a valve assembly for rice pressurized packages whereby easy and reliable filling of canisters equipped with the new valve assembly is ensured, and absolutely no leakage can occur when the spray head is associated with the valve assembly of the filled canister.

Another object of this invention is to achieve the aforementioned improvements in such a manner that the basic features of the valve assembly here under discussion and the conventional means for the filling of the spray canisters do not have to be changed.

A further object of this invention is to provide a novel method for filling spray cans of the character described which enables the valve plunger to seal the container immediately after completion of the filling process in alignment relative to the passageway through which the canister is filled and through which the spray head stem subsequently is inserted.

Further objects and advantages of this invention will become apparent in connection with the following description of a preferred embodiment of this invention including the steps of the method concerned together with the accompanying drawings, wherein:

FIG. 1 is a fragmentary, cross-sectional view taken through the upper part of a spray canister equipped with a self-sealing valve assembly according to the prior art;

FIG. 2 is a view similar to FIG. 1, illustrating the filling of a spray canister through the valve assembly of FIG. l by means of a suitable injector member;

FIG. 3 is a fragmentary elevational view of the upper part of a spray canister with a valve assembly embodying the invention and a tool for filling the canister with pressurized product, portions of the tool being in section to show interior details;

FIG. 4 is a bottom plan View of the tool illustrated in FIG. 3 on a reduced scale;

FIG. 5 is an enlarged sectional view taken along the line 5-5 of FIG. 4 and in the general direction indicated;

FIG. 6 is a fragmentary cross-sectional view of the valve assembly of the invention illustrated in a condition where the injector member is inserted for the purpose of filling but prior to commencing of the actual filling process;

FIG. 7 is a view similar to that of FIG. 6 but illustrating the valve assembly of the invention in the condition assumed during the process of filling the spray canister; and

FIG. 8 is a view similar to that of FIGS. 6 and 7 but illustrating the condition of the valve assembly assumed after interruption of the lling process.

Referring now to the drawing, in FIG. 1, a representative valve assembly is illustrated secured to a pressurized package container 10. Only the upper portion of container 10 is shown in order to illustrate the position of the valve assembly on the spray can. The remaining structure of container 10 has no bearing on the herein invention and therefore, has been omitted.

Container 10 is provided with a comparatively wide openin-g 9 at its upper end into which the cover member 12 carrying the valve assembly designated generally by reference character 20 is inserted The container has a rolled rim 11 surrounding opening 9 to which the cover member 12 is fastened by means of a circumferential bead 13 provided on said cover. The bead 13 fits tightly over rolled rim 11 and a sealing layer 14 is provided between rim 11 and bead 13 to ensure gas-tight connection therebetween.

The circular cover member 12 is provided with a central boss 15 which is deep drawn, for example, directly from the cover member 12. Boss 15 may be of generally cylindrical configuration and is provided with a central hole 16 in its top wall 17.

The valve assembly 20 depends from the upper end of boss 15 into the interior of container 10.

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The valve assembly includes a substantially cylindrical housing 21 provided with an annular flange 22 at its upper end in assembled condition in the boss 15. A gasket 23 of resilient material, such as, rubber or the like is clamped between the flanged end of the housing 21 and top wall 17. 'I he housing 21 is held in place by means of the annular deformation 18 in boss 1S and is biased to a certain extent against the gasket 23. The gasket 23 has acentral opening or bore 24 in registry with central hole 16 in Wall 17 of boss 15. The diameter of hole 16 is only slightly greater than the diameter of opening 24.

The housing 21 has a reduced diameter lower end defining a shoulder 36 whereby to support a cylindrical coil spring 28. A valve plunger 27, preferably made of plastic material, is sandwiched between the upper end of the spring 28 and the inner surface of the gasket 23.

The plunger 27, like housing 21, gasket, and boss 1S, is of generally cylindrically configuration. Plunger 27 has an enlarged section 34 the outer diameter of which corresponds substantially to the inner diameter of the cylindrical housing 21. The enlarged portion 34 is spaced from the lower end of the plunger 27 by a spring seat formation 39 received in the interior of the coil spring 2S whereby to ensure the correct relative position of the plunger and the spring.

The upper portion 35 of plunger 27 above the enlarged section 34 has a socket 33 of cylindrical configuration. The upper rim of the plunger forms a value seat 36 which normally, under the infiuence of the spring 23 sealingly engages the undersurface of gasket 23 thereby preventing product from escaping from the container. The inner diameter of the vertical boundary of a gallery 37 is larger than the diameter of the central bore 24 so that the rim of the central bore 24 is surrounded by the valve seat 35 when the plunger 27 is properly aligned with bore 24.

The socket 33 is adapted to receive snugly a hollow stem 70 shown partially in phantom outlines which depends from spray head 73 also shown partially in phantom outlines. Spray head 73 contains a spray nozzle (not shown) communicating with the socket 33 through the interior of hollow stem 70 and through an axial slot 71 provided in the wall of stem 70. When stem 70 properly is seated within the socket 33, the spray head can be depressed by finger pressure to separate the valve seat 36 from the gasket 23, opening a passageway between the spray nozzle and the interior of the container. This pas-- sageway is completed by a dip tube 32 secured at the lower end of valve housing 21 as by crimp 31 formed in the housing. The lower end of plunger 27 is provided with a transverse notch 3S extending across the entire diameter thereof to provide an area of sufiicient cross-section to permit travel of the pressurized product past the plunger in either direction.

A cylindrical pilot stud 41) is formed at the bottom of socket 33 to define, in cooperation with the inner boundary of socket 33, a space 41 for receiving the lower end of the spray head stem 70 FIG. 2 illustrates the condition under which the filling of the lcontainer from exterior thereof as heretofore known takes place. lt can be noted that spray head 73 is not associated with the can. A suitable injector member t) is inserted through hole and sealingly through bore 2d of the gasket 23, so that discharge orifices S3 provided in the lower end of the injector member Sti are in free communication with socket 33. Injector member 50 is hollow and has channel 51 communicating between the orifices 53 and a source of pressurized product to be introduced into the container 1f). Pressurized product is introduced through the channel 51 and discharged through orifices 53 as shown at 54, past the plunger 27 and via the dip tube 32 into the interior of the container 10.

The pressure of the product introduced through the valve housing 21 affects the plunger 27 to move it toward the lower end of the housing 21 to an extent that spring 28 may be compressed, as illustrated in FIG. 2.

After the container 10 has been entirely lled with pressurized product, the supply of product is discontinued and pressure upon plunger 27 is withdrawn. Under the influence of spring 28, plunger 27 returns to its normal position sealingly engaging the gasket 23 with its valve seat 36 to prevent escape of pressurized product from the container 1o. The injector member 56 is removed from the valve assembly and the pressurized product is ready to be dispensed from the can after insertion of a suitable spray head into the socket 33.

Since it is desirable that the individual parts of the container and of the valve assembly be as inexpensive as possible, they are manufactured by mass production techniques thereby limiting the tolerances of the individual parts. Furthermore, plunger 27 has to be fitted comparatively loosely in the housing 21 in order to minimize friction during movement of the plunger. Thus, the outer diameter of enlarged portion 34 is exceeded slightly by the inner diameter of the housing 21, as shown in FIGS. l, 2, 6, 7 and 8, so that the plunger 27 is movable or shiftable laterally with respect to the housing 27. Such a condition is clearly shown in FIG. l where plunger 27, due to laterally acting components of the pressure of the product or the force of spring 28 is shifted to the left side of the housing 21, leaving the distance 56 at the right side. Consequently, socket 33 and stud 40 are not in coaxial alignment with the central hole 16 or the central bore 24. ln spite of this misalignment, plunger 27 nevertheless will seal the interior of the container 10 and prevent escape of pressurized product.

The spray can is sold with the spray head in place, and hence, after filling, the spray head is installed on the filling line, usually by automatic machinery. In the misaligned condition shown in FIG. l, when inserted, the stem 70 of spray head 73 -lirst penetrates the central bore 16, and then, passes through central bore 24 of the gasket 23. When the spray head is moved further toward the plunger 27, the lower edge 72 thereof engages the plunger 27. The lower edge 72 engages the upper portion of the valve socket 33 only in a very small area located on the right side of the socket 33 in FIG. l. Continuing downward movement, the plunger is first likely to be slightly tilted to the right side until it engages the adjustment wall of the housing so that it is prevented from further tilting. This causes, however, disengagement of the valve seat 36 from the gasket 23 so that pressurized product can escape through the central bore 24. This is a highly undesirable condition resulting in not only loss of product, but also, in possible contamination of the outer surface of the cover member 12. In a filling factory, the filling apparatus would be contaminated and likewise, the atmosphere could be made hazardous from a propellant which is infiammable.

The application of additional pressure to the spray head after the initial tilt of the plunger leads to axial movement of the plunger 27 until the rim thereof completely is disengaged from the gasket 13. Only when this condition has been reached, can spring 28 return the plunger 27 to its correct vertical position. The stem 70 will enter the recess 33 until its lower edge 72 reaches the bottom of the annular space 41, simultaneously shifting the plunger laterally into coaxial alignment with the central bore 24. Subsequently, the plunger can return to its sealing position in coaxial alignment with the bore and the stem respectively. However, the undesired leakage persists until this sealed condition is reached.

In FIG. 3, there is illustrated the fixture 60 used to support injector member 50 with respect to the spray container 1@ to be filled. Fixture 63 can be of conventional structure and does not form a part of this invention so that only a brief description thereof is made. The basic parts of fixture 6l) are a ring 61 supported on top of the container 10 in a self-centering manner, a head member o2 reciprocally mounted with respect to the supporting ring 61 by means of bolts 63, and the injector member 50 associated with the head 62 by means of the insert 65. Channel SI1 of injector member 50 is adapted to be connected to a suitable source of pressurized product. The bolts 63 serve as guiding rods for the head 62 when moved towards the valve assembly during the filling process. The he'ad 62 is lprovided with proper bores warranting -smooth and straight movement of the head 62 along the bolts 63. FIG. 4 illustrates fixture 60 as viewed from below. Springs 64, as represented in FIG. 5, are secured between the movable head 62 and the immobile ring 61 biasing the head part 62 'against the bolt heads 69.

In FIGS. 3 and 6-8 inclusive, the structure embodying the invention is illustrated and substantially corresponds to the previously described valve structure but, the stud portion, now referred to by reference character 40', is provided with a recess 58 instead of 'a at, planar surface 42, as in the prior structure shown in FIGS. 1 and 2. The recess 58 opens towards the adjacent tip 55 of the injector member 50 and is symmetrical with respect to the longitudinal axis of the plunger 27. The recess 58 may be characterized as a pocket of a tapering configuration formed in the stud 40'.

Accordingly, when the injector member approaches plunger 27', tip 55 slides into recess 58, as shown in FIG. y6. Pressurized product is fed through the channel 51 of the injector member in the direction of arrow M and passes through the orifice 53, as shown in FIG. 7. The plunger 27 is separated from the injector member 50 due to the pressure upon the plunger exceeding the force of spring 28.

The next step during the filling process is the discontinuation of the supply of pressurized product. Consequently, the force of the compressed spring 28 acting on the plunger 27 becomes dominant and plunger member 27 is returned in the direction of arrow P to its normal position, as illustrated in FIG. 8. The plunger 27', Ilike the plunger 27 of FIG. 1, is assumed to have been subject to a lateral shifting movement toward one side of the housing. Traveling upwardly, the plunger rst will engage the tip of the injector member at the edge of recess 58. It is apparent that the tapered tip 55 cooperating with recess 58 centers the plunger 27 with respect to the opening of the gasket before the plunger has reached the gasket 23 and therefore, still is movable in a lateral direction. As soon as the plunger is disposed in coaxial alignment with the central bore 24, the tip 55 has entered the pocket 58 to its deepest extent. When such condition has been assumed, the valve seat 36 engages the gasket 23 and keeps the container sealed.

In contrast to the valve assembly of FIGS. 1 and 2, the depending stem 70 of a spray head now can be readily inserted into the socket 33. The lower edge 72 of the spray head stem 70 is capable of reaching the bottom of the annular space 41 directly without causing any intermediate leakage of product due to any lateral movement of the plunger 27'.

It is believed that the structure of the invention including the novel method have been explained sutiiciently to enable one skilled in the art to practice the same. Many variations in relative dimensions, arrangement of parts and steps of the method, are contemplated Without departing from the scope of the invention.

What it is desired to be secured by Letters Patent of the United States is:

1. A method of filling a pressurized package from an exterior source of pressurized product which includes a self-sealing valve assembly having a spring biased plunger reciprocal within a housing between a sealed and unsealed condition and the plunger includes a socket having a coaxial recessed stud formation adapted to engage an exteriorly introduced injector means operatively connected to a source of pressurized product, said method comprising the steps of (a) inserting the injector means sealingly into the socket of the plunger,

(b) introducing pressurized product through said injector means to overcome the bias of said plunger and displace the same from its sealed condition to its unsealed condition,

(c) interrupting the flow of the pressurized product through the injector means, and

(d) simultaneously intercepting the plunger as the same returns to its sealed condition by engaging said injector means within the recessed portion of said stud formation to thereby coaxially guide the plunger to a proper sealed condition notwithstanding lateral displacement thereof during ilow of pressurized product.

2. In combination, an injector member and a valve assembly adapted for use with a spray can for a pressurized product, said valve assembly comprising, a valve housing with a first and second end, a gasket With a central bore opposite the first end of said housing, a valve plunger reciprocal within the said housing and having a valve seat, spring means biasing said plunger toward said gasket with said valve seat sealingly engaged against said gasket and surrounding said central bore, said spray can adapted to be illed with pressurized product injected from the exterior of the valve assembly through said central bore by the injector member, said member having a tip which penetrates said central bore and enters said valve housing a distance insufficient to unseat said plunger, whereby said nozzle may introduce pressurized product into the valve housing which product will axially displace and unseat the valve plunger from said gasket to permt said pressurized product to enter the spray can, said valve plunger having guide means thereon including a tapered coaxial recess adapted to cooperate with said tip, such that when the ow of pressurized product ceases and said Valve plunger is moved axially by the spring means into sealing relationship with said gasket, said tip engages said guide means and centers the valve plunger with respect to said central bore.

3. A combination as delined in claim 2 wherein the plunger has an upper portion including said valve seat and defining a socket opening to said valve seat, said guide means further including a central stud disposed within said socket, said stud having the tapered coaxial recess corresponding in shape to said nozzle tip formed therein.

4. A combination as defined in claim 3 wherein the socket is provided with a gallery formation opening to the gasket.

5. In combination, an injector member and a valve assembly adapted 4for use with a spray can having a cover member with a central hole, said valve assembly adapted to be secured to said cover member and, when so secured, including a valve housing tightly connected to said cover member, a gasket having a central bore in alignment with said central hole between said housing and said cover member, a plunger having a socket for receiving a spray head stem inserted through Said central hole and said central bore, said plunger reciprocal within said housing in the axial direction thereof and having a valve seat at its end adjacent said gasket, spring means normally urging said plunger in sealing engagement against said gasket and coaxially to surround said central bore when in alignment therewith, said injector member adapted to ll said spray can with pressurized product and having a tip insertable in said central hole in sealing engagement with said gasket, said tip entering the valve housing a distance insuficient to unseat the plunger, so that pressurized product can be introduced from said injector member through said valve assembly into said can, said pressurized product unseating said plunger `from said gasket and thereby permitting iilling of said spray can, said plunger at its end adjacent said bore being provided with a tapered recess arranged coaxially with respect to said plunger, said recess adapted matingly to receive said tip of said injector member, so that said plunger is positioned in coaxial alignment With said central hole and said central bore when returning into its sealing position under the influence of said spring means after discontinuing introduction of pressurized product.

6. A combination as set forth in claim S wherein said recess is of conical shape.

7. In combination, injector means and a valve assembly for use with a container for a pressurized product wherein an opening is provided in the container and the valve assembly includes a cover member adapted to be secured in said opening, a housingy secured to the cover member, a plunger reciprocal in the housing, the cover member having a central hole adapted to receive a spray head stem therento and a gasket disposed between the cover member and the housing and having a bore in register with said central hole for Sealing the stem in passing into the assembly, the plunger having a socket to receive the stem when inserted and having a valve seat biased against the gasket to normally prevent passage of pressurized material therepast, the container being adapted to be filled with pressurized product through said hole and said bore subsequent to securement of said valve assembly thereto by said injector means which is insertable from the exterior of said container through Said gasket into said housing, said injector means including a tip which upon filling enters the housing a distance insufficient to unseat the plunger, so that pressurized product can be introduced into said container, said pressurized product unseating said plunger from said gasket and permitting lliug of said container; the invention herein which comprises a tapered guide formation provided in said socket which cooperatively engages said injector tip after the introduction of pressurized product has ceased to ensure coaxial alignment of said socket with said bore notwithstanding lateral shifting of said plunger before the end of the lling process.

References Cited UNITED STATES PATENTS 2,974,453 3/ 1961 Meshberg Z22-402.2 X 3,234,707 2/1966 Weston 141-20 X 3,273,607 9/1966 ONeill 141-20 X FOREIGN PATENTS 1,165,748 6/1958 France.

832,507 4/ 1960 Great Britain.

LAVERNE D. GEIGER, Primary Examiner.

E. EARLS, Assistant Examiner. 

